1. Field of the Invention
The present invention relates to spray heads, to tank-flushing assemblies incorporating one or more such spray heads and to spray application equipment provided therewith e.g. for use in agriculture, horticulture and forestry.
2. Description of the Related Art
In order to decontaminate agricultural spray application equipment after use, normally the spray tank must be filled to the neck with water to rinse chemical solution from all internal surfaces. The washing procedure may have to be repeated several times when changing to a different pesticide. As tractor mounted sprayers commonly have capacities of 1500 liters or more, the volume of contaminated washings generated can be substantial. Where the washings must be sprayed out, this is wasteful of both the land area required and the operators' time.
UK Patent Application No. 8828270 discloses a tank-flushing assembly in which only a fraction of the rinse water hitherto required is sprayed over the inner walls of the tank in a recirculating flow. Reducing the amount of liquid in this way effects a corresponding reduction in the required capacity or area of any disposal facility, and reduces the time needed to clean out the tank(s).
Although such a system is perfectly adequate for smooth walled tanks which are substantially free from internal obstructions, most spray tanks contain one or more internal hoses, as well as other obstructions like the filter basket etc. Some designs, for example, have features moulded into the tanks which cause channelling or separation of the down-wash from the tank walls. In one such design, for example, a channel is moulded around the waistline of the tank to locate a horizontal mounting strap and the resulting protrusion inside the tank interrupts the down-wash from the simple overhead spray heads so that there is a risk of pockets of chemical residue being left behind underneath the protrusion.